Drill



Patented July 2, 1935 UNITED STATES PATENT OFFICE DRILL Gouverneur G. Brown, Brooklyn, N. Y.

Application June 1, 1932, Serial No. 614,688

10 Claims. (Cl. 255-64) This invention relates to drills and especially to rock drills.

It is the object of this invention to provide a simple, cheap and efficient construction securing firm attachment of the drill bit to the shank end' 5 In the drawing:

Figure 1 is a perspective view of the drill bit; Figure 2 is a perspective view of the shank end; Figure 3 is a top sectional view of the drill bit and shank end in initial assembly position; and

Figure 4 is a top sectional view similar to Figure 3 with the parts in completed assembly or operating position for drilling in one direction.

Referring to the drawing, the drill bit shown comprises a body member having integral drill teeth 2 at one end and a hollow extension or sleeve 3, preferably formed integrally therewith, at the opposite end, providing a socket for placement upon a shank end 4 and securing an extended sleeve engagement of the drill bit with the shank end.

In accordance with the present invention, the connection means for these parts is designed and arranged to provide forces upon the parts which always tend to tighten the end bearing and sleeve engagement of the parts and preferably are operative in either direction of operation, viz, drilling or back drilling.

For this purpose the sleeve 3 carries on itsinner periphery a projection or lug 5 which may, with advantage, be formed integrally therewith, and of elongated form with its inner surface inclined inwardly toward the center of the sleeve from its lower end upward, substantially as shown, and

this inclined surface hollowed slightly to form an 1 to permit the passage of lug 5 through the larger part of the taper I.

The taper expands circumferentially, preferably on each side of the slot, as shown, so as to form cam surfaces coacting with the lug 5 to 5 force the shank end against'the sleeve as the shank and bit are rotated relatively to each other, which action at the same time forces the shank end downward against the bit. The preferred construction shown, with the cam surfaces 10 on each side of the slot, provides for drilling in either direction of rotation of the bit. If a single direction drill is desired, the cam surface may be formed only on one side of the slot.

In connecting the drill bit and the shank end 15 4, the shank end 4 is inserted in the sleeve 3 with the groove 8 in alignment with the tapered lug 5 until the base of the shank end contacts with the body I of the drill bit. The shank end 4 is then turned to the right or left in accordance 20 with the operation of the drilling machine, when the tapered lug 5 is moved free of the groove 8 within the reduced portion of the taper I, and because of the eccentricity of the taper I and the cooperating inclined surfaces on the lug 5 and 25 taper 1, cooperates therewith to force the shank end 4 into tight contact with the drill body I and the sleeve 3. The contact positions of the shank and sleeve are concentric in the fully assembled or operative position of the parts.

When the connection is completed, the undercut shoulder 6 is preferably well within the sleeve 3 to provide substantial engagement of the sleeve 3 and shank end 4 thereabove, and the inner periphery of sleeve 3 opposite lug 5 preferably will be 35 slightly relieved at 9 to secure three point bearing between the sleeve and shank to compensate for inaccurate steel sections and avoid the rocking incident to two point bearing. No key is necessary, but a key pin may be passed through 40 the parts from side to side if desired to 'hold them in assembled position when not operating.

While the invention is shown as applied to a round shank end, a very important advantage resides in its applicability to shank ends of all 45 standard stocks. A further advantage is that. no especial tools, dies or machines are necessary in producing the construction, as it may readily be accomplished upon an ordinary emery wheel or grind-stone.

It will be understood that reversal of the parts on which the lug and eccentric are placed is possible and that other modifications may be made within the invention .as defined by the claims.

What is claimed is:

1. A rotary drill having a sleeve connection on the shank comprising two members, an eccentric surface on one of the members cooperating with a lug on the other member to force the members of the sleeve connection into sidewise binding contact on relative rotation of the shank and hit, one of the engaging surfaces on the sleeve connection being tapered longitudinally of the shank to force the parts together longitudinally on such relative rotation.

2. A drill comprising a bit, a drill shank, a sleeve connection between the shank and bit, 9. lug carried by one of the members of the sleeve connection, and an eccentric surface on the other member cooperating with the lug to force the shank and sleeve into sidewise binding contact on relative rotation of the shank and bit, said lug and eccentric surface being tapered longitudinally of the shank in opposite directions, whereby the relative rotation of the shank and bit forces them together longitudinally of the shank,

3. A drill comprising a bit, a drill shank, a sleeve connection between the shank and bit, a lug carried by one of the members of the sleeve connection, the other member having a groove extending longitudinally of the shank and adapted to receive the lug, and an eccentric surface on each side of said groove cooperating with the lug to force the shank and sleeve into binding sidewise contact on relative rotation of the shank and bit in either direction.

4. A drill comprising a bit, a drill shank, a sleeve connection between the shank and bit, a lug carried by one of the members of the sleeve connection, the other member having a groove extending longitudinally of the shank and adapted to receive the lug, and an eccentric surface on each side of said groove cooperating with the lug to force the shank and sleeve into binding sidewise contact on relative'rotation of the shank and bit in either direction, said lug and eccentric surface being tapered longitudinally of the shank in opposite directions, whereby the relative rotation of the shank and bit forces them together longitudinally of the shank.

5. A drill comprising a bit, a drill shank, a sleeve connection between the shank and bit, a lug carried by the inner periphery of the sleeve, a groove on the shank extending longitudinally of the shank and adapted to pass the lug, and an eccentric surface on the shank on each side of the groove cooperating with the lug to force the shank and sleeve into binding sidewise contact on relative rotation of the shank and bit in either direction.

6. A drill comprising a bit, a drill shank, a sleeve connection between the shank and bit, a

lug carried by the inner periphery of the sleeve, a groove on the shank extending longitudinally of the shank and adapted to pass the lug, and an eccentric surface on the shank on each side of the groove cooperating with the lug to force the shank and sleeve intobinding sidewise contact on relative rotation of the shank and bit in either direction, said lug and eccentric surface being tapered longitudinally of the shank in opposite directions, whereby the relative rotation of the shank and bit forces them together longitudinally of the shank.

7. A drill comprising a bit, a drill shank, a sleeve connection between the shank and bit, a lug carried by one of the members of the sleeve connection, an eccentric surface on the other member cooperating with the lug to force the shank and sleeve into sidewise binding contact on relative rotation of the shank and bit, and a recess in one of said sleeve connection members to relieve the binding contact over a portion of the shank and sleeve to provide a three point bearing between the shank and sleeve.

8. A bit having sleeve 3 with tapered lug 5 on its inner periphery, in combination with shank 1 having shoulder 6, groove 8 receiving the lug and eccentric surfaces 1 undercut on the shank, on each side of the groove and tapered oppositely to the lug from the end of the shank to the shoulder 6, said shank and sleeve being in concentric position when the parts are locked together by the relative rotation of the lug and eccentric surfaces on the shank.

9. A bit having sleeve 3 with longitudinally tapered lug 5 on its inner periphery, in combination with shank 4 having shoulder 6, groove 8 receiving the lug, and eccentric surface 1 undercut on the shank and tapered oppositely to the lug from the end of the shank to the shoulder 6, said shank and sleeve being in concentric position when the parts are locked together by the relative rotation of the lug and eccentric surface.

10. The combination with a drill bit and its shank, of a sleeve connection between the bit and shank having 9. lug on one of the members of the sleeve connection, a slot on the other member permitting a larger diameter portion of said member to pass the lug in assembling the parts longitudinally, a reduced diameter portion on the slotted member in line transversely with the lug in assembled position, and engaging surfaces on the lug and reduced portion coacting to force the bit and shank together sidewise and longitudinally on relative rotation of the bit and shank, whereby a combined bayonet joint and sidewise and longitudinal locking of the parts is provided.

GOUVERNEUR G. BROWN. 

